Telecommunications systems, cable television systems and data communication networks use optical networks to rapidly convey large amounts of information between remote points. In an optical network, information is conveyed in the form of optical signals through optical fibers. Optical fibers comprise thin strands of glass capable of communicating the signals over long distances with very low loss. Optical networks often employ redundancies to maximize performance and availability. Such redundancies may include optical unidirectional path switched ring (OUPSR). With OUPSR, an optical signal may be transmitted via two or more optical paths between the same source and destination node. An OUPSR device at the destination may include a photodetector per each path to monitor signals received from the two or more paths. Based on such received signals, the OUPSR device may select one of the signals to be forwarded to a transponder or receiver at the destination node. For example, the OUPSR may determine, based on the photodetector monitoring, whether one of the paths has experienced a loss of signal or “loss of light.” If a particular path experiences a loss of light, then the OUPSR may select another path to forward to the transponder or receiver. Such selection may be referred to as a “protection switch.”
A particular communication network may include a plurality of network elements for carrying Ethernet traffic between two or more clients via a synchronous optical network (SONET), Optical Transport Network (OTN), or another suitable network. End-to-end latency between clients in an OTN or SONET network may vary between end-to-end paths based on the number of links in a path, regeneration of paths, and other factors. In addition, latency for a single path may vary over time due to reconfiguration of the network. Latency is a prime importance for many applications, and customers of a network may pay premiums such that their network traffic experiences the smallest amount of latency. However, relevant SONET and OTN standards do not provide a way to calculate end to end latency to allow selection of an OTN or SONET path based on latency for an individual Ethernet flow.